No shame in it, and I don't consider it a waste of time. Keeps your mind sharper than watching TV or Youtube anyway.Good for you man. It's one of my main hobbies.
As for my favorite game... My love of cars likely stems from playing the Gran Turismo games growing up. 4 and 5 stand out the most to me, can't decide on the fave. Always used a force feedback wheel setup and transitioned into games like Assetto and iRacing later on.
Bonus about racing sims is that it keeps you surprisingly sharp for IRL racing. I was shredding my karting league races after a season off only doing the sim.